I took this back in June, so it does not qualify for the current black and white challenge/high contrast. Still, when I saw the challenge I thought of this shot and decided to give it a go anyway. I'll get a current shot before the challenge ends and submit a valid entry then.
Thank you Phoebe, Suse, Karen, Katy, and Daisy!
@grammyn Very close! It's the propeller on a WWII plane.